1. Field of the Invention
This invention relates to a structure of plasma display panels.
The present application claims priority from Japanese Application No. 2004-263772, the disclosure of which is incorporated herein by reference.
2. Description of the Related Art
A surface-discharge-type alternating-current plasma display panel (hereinafter referred to as “PDP”) has two opposing glass substrates placed on either side of a discharge-gas-filled discharge space. One of the two glass substrates has row electrode pairs extending in the row direction and regularly arranged in the column direction. The other glass substrate has column electrodes extending in the column direction and regularly arranged in the row direction. Unit light emission areas (discharge cells) are formed in matrix form in positions corresponding to the intersections between the row electrode pairs and the column electrodes in the discharge space.
The PDP further has a dielectric layer provided for covering the row electrodes or the column electrodes. A magnesium oxide (MgO) film is formed on a portion of the dielectric layer facing each of the unit light emission areas. The MgO film has the function of protecting the dielectric layer and the function of emitting secondary electrons into the unit light emission area.
The MgO film of such conventional PDPs is formed by the use of a screen printing technique to apply a coating of a paste containing an MgO powder mixture onto the dielectric layer. Such a conventional MgO film is suggested in Japanese Patent Laid-open Application No. 6-325696, for example.
However, the conventional MgO film is formed by use of a screen printing technique to apply a coating of a paste mixed with a polycrystalline floccule type magnesium oxide obtained by heat-treating and purifying magnesium hydroxide. Therefore, this MgO film thus formed provides the discharge characteristics of the PDP merely to an extent equal to or slightly greater than that provided by a magnesium oxide film formed by the use of evaporation technique.
An urgent need arising from this is to form a protective film capable of yielding a greater improvement in the discharge characteristics of the PDP.